Over the years, different mechanized vehicle washing systems have been designed to eliminate the need to scrub vehicles manually with large spongy mittens and the like. Remotely or automatically controlled finishing devices, in the form of brushes, rollers, sponges, cloths, pads, etc., have been used in such mechanized vehicle washing systems to wash, wax, polish or buff the surface of a vehicle. Brush assemblies and curtain assemblies are two types of finishing devices commonly found on modern automatic vehicle washing systems.
A typical brush assembly includes a drum which is mounted for rotation about a substantially vertical axis and which is equipped with a plurality of elongated brush elements,, such as bristles or plastic filaments, adapted to contact an exterior surface of a vehicle undergoing a washing or other finishing operation. Since bristles can be harsh on the vehicle surface and might even cause unwanted scratches, it is a popular practice to replace the bristles with flexible felt pads.
In a brush assembly in which the brush elements are made from a plurality of flexible felt pads, the outer circumferential surface of the drum is provided with a series of longitudinally extending slots. Each slot is sized and shaped so as to releasably receive a looped or beaded end of an associated felt pad. The opposite or free end of each pad has a large number of parallel slits projecting inwardly toward the looped or beaded end of the pad to thereby form a plurality of elongated fingers which contact the vehicle surface to perform the desired finishing operation.
In a typical curtain assembly, a number of curtain elements, each of which consists of a length of carpeting, fabric, felt or plastic material, are mounted side-by side from a substantially horizontal support rod. It is common, but not necessary, to move the support rod in a reciprocating or oscillating fashion for the purpose of imparting a swinging motion to the curtain elements depending therefrom. Whether they are stationary or swinging, the curtain elements have free ends which contact the vehicle surface to perform the desired finishing operation.
Although the use of finishing elements formed from felt pads, whether used as brush elements or curtain elements, minimizes any undesirable scratching of the vehicle surface, the felt pads themselves are subject to considerable wear due to their repetitive contact with the vehicle surface. In fact, the free or "working" ends of such pads are literally worn off, thereby shortening the overall length of the brush or curtain element to an extent which prevents it from contacting the vehicle. Thus, the entire vehicle washing system must be shut down so that the worn finishing elements can be removed and replaced. In addition to undesired operating downtime, there is the increased cost of replacing the entire brush and/or curtain element. Since this cost is relatively expensive, brush and/or curtain replacement significantly increase the cost of maintaining and operating the vehicle washing system. Because of the increased cost, operators tend to utilize worn pads for excessive periods of time, thus causing a decrease in the efficiency of the vehicle washing system.
In the past, various proposals have been made to eliminate or minimize the wear problem associated with the brush assemblies and the curtain assemblies discussed above. For instance, Clark U.S. Pat. Nos. 4,567,619 and 4,653,135 disclose a brush assembly finishing element formed as a cloth pad which can be adjusted in length to compensate for wear. The adjusting means includes a plurality of loops formed in the cloth pad, each loop being adapted for insertion into a groove on a periphery of a drum. Beer U.S. Pat. No. 4,603,447 relates to a disk-type brush whose diameter may be varied to permit field adjustment for brush wear. Crotts et al. U.S. Pat. No. 5,148,570 discloses an adjustable curtain assembly that uses a roller bar to adjust the length of an entire bank of curtain elements. Curtain elements have also been removably attached to a support rod through the use of Velcro fasteners (see, for instance, Moran U.S. Pat. No. 3,940,821; Kim U.S. Pat. No. 4,166,302; Seveny U.S. Pat. No. 4,756,040; and Weigele U.S. Pat. No. 4,967,442.)